This invention relates to an accessory device applicable to a power tool such as a power hand drill which allows for a quick change of the tool being used in the chuck of the mechanism. The accessory is interposed between the drill and the tool, typically by retaining the tool retention device in the drill chuck. The device according to the invention allows for extremely quick changing of the tool so that merely by depressing a button on the device is the tool released from its fixed operative position. No longer is it necessary to use a key to unlock the drill chuck first before removing the bit or other tool being used so as to change it.
There are other devices reflecting numerous attempts to improve upon hand and power tools to make them more readily useable or more quickly changeable. An example of this is the patent to Smith U.S. Pat. No. 1,833,236 in which the tool retainer device is spring loaded but in which action must be taken against the spring pressure and also a rotational movement applied so as to lock a pin and therefore the head of the tool.
Swedish Pat. No. 31586 shows a J-clamp about the upper portion of which is positioned a spring, so that when a tool is to be removed from a hole in the body, the head of the J-clamp is depressed.
The patent to Hoffmeister U.S. Pat. No. 3,604,735 depicts another locking means in which a member is spring-loaded so that a push on the end will cause a hook to be released from the tool being held.
Canadian Pat. No. 699,619 teaches a quick change chuck for drills using a canted annular member that is activated by a button on the side of the chuck.
The patent to Richard U.S. Pat. No. 2,215,015 and to Beck U.S. Pat. No. 3,255,792 also teach spring-biased tool holders that allow a tool to be released and replaced quickly.
None of the foregoing prior art has achieved the simplicity and the ease of manufacture and of change of a tool that is achieved by the instant invention.